[Dimensio]

According to our known laws of physics, the sunlight would be required to sustain plant life, would it not?

Yes, and without the sunlight being present for a good while beforehand, the newly created plants and animals would have instantly frozen to death.

[DannyTN]

"According to our known laws of physics, the sunlight would be required to sustain plant life, would it not?"

Nah. You are only talking 1 day. And God created light before he created the Sun.

In order to prove God didn't do what is recorded in Genesis, you have to know the extent of God's knowledge and abilities.